In the realm of practical clinical medicine there is no one feature that gives strength to the art and science like that of making a diagnosis. Upon this foundation—diagnosis—must be erected the superstructure of the case, embracing all of the primary essentials, of which it may be said that prognosis, by its approach to the personal element in the case, becomes of very great importance. Prognosis, then, is necessarily founded upon diagnosis. However, there enter into its consideration certain basic or fundamental essentials which make it both an art and a science.

Of the essentials contributing to make prognosis an art we will mention the ability to give estimates based upon experience. Herein are noted the deductions which acuity of observation and abstract reasoning give to the clinician, the quality of the observer which gives color to his art in diagnosis. Again, the cultivation of these faculties